By Ania Lichtarowicz
BBC health correspondent in Geneva
The newly elected leader of the World Health Organization, Dr Jong-wook Lee, has said fighting Aids will be at the top of his agenda.
Dr Lee - a tuberculosis expert from South Korea who takes over from Gro Harlem Brundtland - says he wants to tackle HIV and ensure that as many people as possible can receive anti-retroviral therapy.
Dr Lee is a proven leader and administrator
"HIV/Aids is a big problem... 27 million people are infected in Africa and globally nearly 50 million people are suffering from this," Dr Lee said.
"But my view is now that there is good international will to do something real and practical."
Dr Lee was elected as director general on a day when the WHO unanimously adopted an anti-smoking treaty - the first global public health measure ever approved.
Dr Lee is already a proven leader and administrator.
He is the former head of the agency's "Stop Tuberculosis" campaign.
His ambitions for the WHO also include tackling poverty and improving the global outbreak alert-and-response network, which has proved essential in monitoring the spread of Sars.
Most HIV drugs are beyond the means of most Africans
Getting anti-retroviral drugs for HIV in countries like Africa is a realistic goal, says Dr Lee.
Currently, even generic versions are well beyond the means of most Africans, but the prices must come down, and he says they will.
Vaccinations against polio, which is on the verge of being eradicated, only cost $0.09 each, yet even 20 years ago the treatment was much too expensive to consider such a grand-scale immunisation campaign.
Dr Lee will also face new medical dilemmas like gene therapy, and following the signing of the first ever global health treaty against tobacco, he has a lot to live up to.